Mixing slab for porcelain fillings



Dec-21,1949 w. H. HOWARD 2,492,479

MIXING SLAB FOR PORCELAIN FILLINGS Filed Oct. 50, 1947 2 Shets-Sheet 1 4, 7/517. flaw wd INVENTOR ATTORNEYS Dec. 27, 1949 w, HQWARD 2,492,479

7 MIXING SLAB FOR PORCELAIN FILLINGS Filed Oct. so, 1947 2 Sheets-Sheet 2 ATTORNEYS.

Patented Dec. 27, 1949 UNITED STATES PATENT OFFICE MIXING SLAB FOR PORCELAIN FILLINGS William H. Howard, Barnsdall, Okla.

Application October 30, 1947, Serial No. 783,094

1 Claim.

By way of explanation, it might be stated that to properly mix cements or porcelains in the dental profession, it is important to maintain the cements or porcelain cool, in order to obtain the best results in the finished filling. It is, therefore, the primary object of the invention to provide a dental mixing slab designed for use in mixing cements and porcelains, the slab being provided with means to accommodate a cooling medium to maintain the temperature of the slab at a low degree.

Referring to the drawings:

Figure 1 is a perspective view of a mixing slab constructed in accordance with the invention.

Fig. 2 is a longitudinal sectional view through the slab.

Fig. 3 is a transverse sectional view through the slab.

Fig. 4 is a bottom plan view of the slab illustrating a rectangular recess as formed therein.

Fig. 5 is a bottom plan view of the slab illustrating an oval recess formed therein.

Fig. 6 is a plan view of a modified form of the invention.

Fig. 7 is a sectional view taken on line '|--'I of Fig. 6.

Fig. 8 is a sectional view taken on line 8-8 of Fig. 6.

Referring to the drawings in detail, in the form of the invention as shown by Fig. l of the drawings, the reference character 5 indicates a plate formed with ribs 6, arranged in longitudinal spaced relation with respect to each other, the ribs being formed along the upper longitudinal edges of the plate.

The slab constituting the subject matter of the present invention, is indicated by the reference character l, the slab being formed of any desirable material, preferably glass.

The upper working surface of the slab is flat. so that the porcelain or cement may be properly worked thereon, in the usual and well known manner.

In the lower or bottom surface of the slab, is formed the recess 8 for the reception of the cooling medium, which is of a construction to completely fill the recess, the cooling medium comprising a quantity of cotton batting 13 on which is sprayed ethyl chloride, which has a cooling effect that is transmitted to the working surface of the slab to be absorbed by the porcelain or cement being worked.

It is obvious that when the cooling medium is placed within the recess, and the recessed surface of the slab positioned on the plate 5, as shown by Fig. 2 of the drawings, the cooling medium will be retained within the recess to accomplish its purpose. The recess may be of rectangular formation, as indicated at 9, or it may be oval as indicated at In, in Fig. 5. However, it is to be understood that the recess may be of any desired contour without departing from the spirit of the invention.

In the form of the invention as shown in Fig. 7 of the drawings, I have provided a base plate II, in which a recess I2 is formed, the recess being in the upper surface of the plate, in which recess cotton batting l3, saturated or sprayed with ethyl chloride is placed, the working slab indicated at M being then positioned on the upper surface of the plate ll directly over the cotton batting closing the recess.

In this form of the invention the working slab will be maintained cool by the action of the ethyl chloride.

From the foregoing it will be seen that due to the construction shown and described, I have provided a working slab for use by dentists in Working porcelains and cements, wherein the working surface and material under operation will be maintained cool, insuring a better working of the porcelains or cements than is possible when the porcelains or cements are worked on known slabs now in common use by dentists.

Having thus described the invention, what is claimed is:

A mixing slab on which dental porcelains and cements are mixed, comprising a plate, upstanding ribs formed along the longitudinal side edges of the plate, an upper slab constructed of glass material having a recess disposed centrally in the lower surface thereof, said recess providing a compartment, in which a cooling medium substantially filling the compartment in contact with the upper slab is held, the upper slab being fitted on the plate with the compartment disposed downwardly, and said slab being disposed between the ribs holding the upper slab to the plate.

WILLIAM H. HOWARD.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,497,890 Bros June 17, 1924 1,754,594 Bens Apr. 15, 1930 1,877,616 Strelitz Sept. 13, 1932- 1,980,533 Kile Nov. 13, 1934 

